[ViewVC] Diff of: cvs/rxvt-unicode/src/perl/background

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.42 by root, Sun Jun 10 10:42:19 2012 UTC vs.
Revision 1.56 by root, Thu Jun 14 17:06:57 2012 UTC

…		…
1	#! perl	1	#! perl
2		2
3	#:META:X_RESOURCE:%.expr:string:background expression	3	#:META:X_RESOURCE:%.expr:string:background expression
4	#:META:X_RESOURCE:%.border.:boolean:respect the terminal border	4	#:META:X_RESOURCE:%.border:boolean:respect the terminal border
5		5	#:META:X_RESOURCE:%.interval:seconds:minimum time between updates
6	#TODO: once, rootalign
7		6
8	=head1 NAME	7	=head1 NAME
9		8
10	background - manage terminal background	9	background - manage terminal background
11		10
12	=head1 SYNOPSIS	11	=head1 SYNOPSIS
13		12
14	urxvt --background-expr 'background expression'	13	urxvt --background-expr 'background expression'
15	--background-border	14	--background-border
		15	--background-interval seconds
16		16
17	=head1 DESCRIPTION	17	=head1 DESCRIPTION
18		18
19	This extension manages the terminal background by creating a picture that	19	This extension manages the terminal background by creating a picture that
20	is behind the text, replacing the normal background colour.	20	is behind the text, replacing the normal background colour.
57		57
58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the	58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the
59	image to the window size, so it relies on the window size and will	59	image to the window size, so it relies on the window size and will
60	be reevaluated each time it is changed, but not when it moves for	60	be reevaluated each time it is changed, but not when it moves for
61	example. That ensures that the picture always fills the terminal, even	61	example. That ensures that the picture always fills the terminal, even
62	after it's size changes.	62	after its size changes.
63		63
64	=head2 EXPRESSIONS	64	=head2 EXPRESSIONS
65		65
66	Expressions are normal Perl expressions, in fact, they are Perl blocks -	66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
67	which means you could use multiple lines and statements:	67	which means you could use multiple lines and statements:
…		…
71	return scale load "$HOME/weekday.png";	71	return scale load "$HOME/weekday.png";
72	} else {	72	} else {
73	return scale load "$HOME/sunday.png";	73	return scale load "$HOME/sunday.png";
74	}	74	}
75		75
76	This expression gets evaluated once per hour. It will set F<sunday.png> as	76	This expression is evaluated once per hour. It will set F<sunday.png> as
77	background on Sundays, and F<weekday.png> on all other days.	77	background on Sundays, and F<weekday.png> on all other days.
78		78
79	Fortunately, we expect that most expressions will be much simpler, with	79	Fortunately, we expect that most expressions will be much simpler, with
80	little Perl knowledge needed.	80	little Perl knowledge needed.
81		81
…		…
99	its result becomes the argument to the C<scale> function.	99	its result becomes the argument to the C<scale> function.
100		100
101	Many operators also allow some parameters preceding the input image	101	Many operators also allow some parameters preceding the input image
102	that modify its behaviour. For example, C<scale> without any additional	102	that modify its behaviour. For example, C<scale> without any additional
103	arguments scales the image to size of the terminal window. If you specify	103	arguments scales the image to size of the terminal window. If you specify
104	an additional argument, it uses it as a percentage:	104	an additional argument, it uses it as a scale factor (multiply by 100 to
		105	get a percentage):
105		106
106	scale 200, load "$HOME/mypic.png"	107	scale 2, load "$HOME/mypic.png"
107		108
108	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>	109	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
109	has now two arguments, the C<200> and the C<load> expression, while	110	has now two arguments, the C<200> and the C<load> expression, while
110	C<load> only has one argument. Arguments are separated from each other by	111	C<load> only has one argument. Arguments are separated from each other by
111	commas.	112	commas.
112		113
113	Scale also accepts two arguments, which are then separate factors for both	114	Scale also accepts two arguments, which are then separate factors for both
114	horizontal and vertical dimensions. For example, this halves the image	115	horizontal and vertical dimensions. For example, this halves the image
115	width and doubles the image height:	116	width and doubles the image height:
116		117
117	scale 50, 200, load "$HOME/mypic.png"	118	scale 0.5, 2, load "$HOME/mypic.png"
118		119
119	Other effects than scalign are also readily available, for exmaple, you can	120	Other effects than scaling are also readily available, for example, you can
120	tile the image to fill the whole window, instead of resizing it:	121	tile the image to fill the whole window, instead of resizing it:
121		122
122	tile load "$HOME/mypic.png"	123	tile load "$HOME/mypic.png"
123		124
124	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	125	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator
…		…
150	This only works for one cycle though, so as long as you load the same	151	This only works for one cycle though, so as long as you load the same
151	image every time, it will always be cached, but when you load a different	152	image every time, it will always be cached, but when you load a different
152	image, it will forget about the first one.	153	image, it will forget about the first one.
153		154
154	This allows you to either speed things up by keeping multiple images in	155	This allows you to either speed things up by keeping multiple images in
155	memory, or comserve memory by loading images more often.	156	memory, or conserve memory by loading images more often.
156		157
157	For example, you can keep two images in memory and use a random one like	158	For example, you can keep two images in memory and use a random one like
158	this:	159	this:
159		160
160	my $img1 = load "img1.png";	161	my $img1 = load "img1.png";
…		…
188	overwriting borders and any other areas, such as the scrollbar.	189	overwriting borders and any other areas, such as the scrollbar.
189		190
190	Specifying this flag changes the behaviour, so that the image only	191	Specifying this flag changes the behaviour, so that the image only
191	replaces the background of the character area.	192	replaces the background of the character area.
192		193
		194	=item --background-interval seconds
		195
		196	Since some operations in the underlying XRender extension can effectively
		197	freeze your X-server for prolonged time, this extension enforces a minimum
		198	time between updates, which is normally about 0.1 seconds.
		199
		200	If you want to do updates more often, you can decrease this safety
		201	interval with this switch.
		202
193	=back	203	=back
194		204
195	=cut	205	=cut
196		206
		207	our %_IMG_CACHE;
197	our $HOME;	208	our $HOME;
198	our ($self, $old, $new);	209	our ($self, $old, $new);
199	our ($x, $y, $w, $h);	210	our ($x, $y, $w, $h);
200		211
201	# enforce at least this interval between updates	212	# enforce at least this interval between updates
202	our $MIN_INTERVAL = 1/100;	213	our $MIN_INTERVAL = 6/59.951;
203		214
204	{	215	{
205	package urxvt::bgdsl; # background language	216	package urxvt::bgdsl; # background language
		217
		218	use List::Util qw(min max sum shuffle);
206		219
207	=head2 PROVIDERS/GENERATORS	220	=head2 PROVIDERS/GENERATORS
208		221
209	These functions provide an image, by loading it from disk, grabbing it	222	These functions provide an image, by loading it from disk, grabbing it
210	from the root screen or by simply generating it. They are used as starting	223	from the root screen or by simply generating it. They are used as starting
…		…
215	=item load $path	228	=item load $path
216		229
217	Loads the image at the given C<$path>. The image is set to plane tiling	230	Loads the image at the given C<$path>. The image is set to plane tiling
218	mode.	231	mode.
219		232
220	Loaded images will be cached for one cycle.	233	Loaded images will be cached for one cycle, and shared between temrinals
		234	running in the same process (e.g. in C<urxvtd>).
221		235
		236	=item load_uc $path
		237
		238	Load uncached - same as load, but does not cache the image. This function
		239	is most useufl if you want to optimise a background expression in some
		240	way.
		241
222	=cut	242	=cut
		243
		244	sub load_uc($) {
		245	my ($path) = @_;
		246
		247	$_IMG_CACHE{$path} \|\| do {
		248	my $img = $self->new_img_from_file ($path);
		249	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		250	$img
		251	}
		252	}
223		253
224	sub load($) {	254	sub load($) {
225	my ($path) = @_;	255	my ($path) = @_;
226		256
227	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	257	$new->{load}{$path} = $old->{load}{$path} \|\| load_uc $path;
228	}	258	}
229		259
230	=item root	260	=item root
231		261
232	Returns the root window pixmap, that is, hopefully, the background image	262	Returns the root window pixmap, that is, hopefully, the background image
…		…
236	reevaluated when the bg image changes.	266	reevaluated when the bg image changes.
237		267
238	=cut	268	=cut
239		269
240	sub root() {	270	sub root() {
241	$new->{rootpmap_sensitive} = 1;	271	$new->{again}{rootpmap} = 1;
242	die "root op not supported, exg, we need you";	272	$self->new_img_from_root
243	}	273	}
244		274
245	=item solid $colour	275	=item solid $colour
246		276
247	=item solid $width, $height, $colour	277	=item solid $width, $height, $colour
…		…
260	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	290	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);
261	$img->fill ($colour);	291	$img->fill ($colour);
262	$img	292	$img
263	}	293	}
264		294
265	=back	295	=item clone $img
266		296
267	=head2 VARIABLES	297	Returns an exact copy of the image. This is useful if you want to have
		298	multiple copies of the same image to apply different effects to.
268		299
269	The following functions provide variable data such as the terminal window
270	dimensions. They are not (Perl-) variables, they jsut return stuff that
271	varies. Most of them make your expression sensitive to some events, for
272	example using C<TW> (terminal width) means your expression is evaluated
273	again when the terminal is resized.
274
275	=over 4
276
277	=item TX
278
279	=item TY
280
281	Return the X and Y coordinates of the terminal window (the terminal
282	window is the full window by default, and the character area only when in
283	border-respect mode).
284
285	Using these functions make your expression sensitive to window moves.
286
287	These functions are mainly useful to align images to the root window.
288
289	Example: load an image and align it so it looks as if anchored to the
290	background.
291
292	move -TX, -TY, load "mybg.png"
293
294	=item TW
295
296	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
297	terminal window is the full window by default, and the character area only
298	when in border-respect mode).
299
300	Using these functions make your expression sensitive to window resizes.
301
302	These functions are mainly useful to scale images, or to clip images to
303	the window size to conserve memory.
304
305	Example: take the screen background, clip it to the window size, blur it a
306	bit, align it to the window position and use it as background.
307
308	clip move -TX, -TY, blur 5, root
309
310	=cut	300	=cut
311		301
312	sub TX() { $new->{position_sensitive} = 1; $x }
313	sub TY() { $new->{position_sensitive} = 1; $y }
314	sub TW() { $new->{size_sensitive} = 1; $w }
315	sub TH() { $new->{size_sensitive} = 1; $h }
316
317	=item now
318
319	Returns the current time as (fractional) seconds since the epoch.
320
321	Using this expression does I<not> make your expression sensitive to time,
322	but the next two functions do.
323
324	=item again $seconds
325
326	When this function is used the expression will be reevaluated again in
327	C<$seconds> seconds.
328
329	Example: load some image and rotate it according to the time of day (as if it were
330	the hour pointer of a clock). Update this image every minute.
331
332	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
333
334	=item counter $seconds
335
336	Like C<again>, but also returns an increasing counter value, starting at
337	0, which might be useful for some simple animation effects.
338
339	=cut
340
341	sub now() { urxvt::NOW }
342
343	sub again($) {
344	$new->{again} = $_[0];
345	}
346
347	sub counter($) {	302	sub clone($) {
348	$new->{again} = $_[0];	303	$_[0]->clone
349	$self->{counter} + 0
350	}	304	}
351		305
352	=back	306	=item merge $img ...
		307
		308	Takes any number of images and merges them together, creating a single image containing them all.
		309
		310	=cut
		311
		312	sub merge(@) {
		313	#TODO
		314	}
353		315
354	=head2 TILING MODES	316	=head2 TILING MODES
355		317
356	The following operators modify the tiling mode of an image, that is, the	318	The following operators modify the tiling mode of an image, that is, the
357	way that pixels outside the image area are painted when the image is used.	319	way that pixels outside the image area are painted when the image is used.
…		…
387	become transparent. This mode is most useful when you want to place an	349	become transparent. This mode is most useful when you want to place an
388	image over another image or the background colour while leaving all	350	image over another image or the background colour while leaving all
389	background pixels outside the image unchanged.	351	background pixels outside the image unchanged.
390		352
391	Example: load an image and display it in the upper left corner. The rest	353	Example: load an image and display it in the upper left corner. The rest
392	of the space is left "empty" (transparent or wahtever your compisotr does	354	of the space is left "empty" (transparent or whatever your compositor does
393	in alpha mode, else background colour).	355	in alpha mode, else background colour).
394		356
395	pad load "mybg.png"	357	pad load "mybg.png"
396		358
397	=item extend $img	359	=item extend $img
398		360
399	Extends the image over the whole plane, using the closest pixel in the	361	Extends the image over the whole plane, using the closest pixel in the
400	area outside the image. This mode is mostly useful when you more complex	362	area outside the image. This mode is mostly useful when you use more complex
401	filtering operations and want the pixels outside the image to have the	363	filtering operations and want the pixels outside the image to have the
402	same values as the pixels near the edge.	364	same values as the pixels near the edge.
403		365
404	Example: just for curiosity, how does this pixel extension stuff work?	366	Example: just for curiosity, how does this pixel extension stuff work?
405		367
…		…
431	$img	393	$img
432	}	394	}
433		395
434	=back	396	=back
435		397
436	=head2 PIXEL OPERATORS	398	=head2 VARIABLE VALUES
437		399
438	The following operators modify the image pixels in various ways.	400	The following functions provide variable data such as the terminal window
		401	dimensions. They are not (Perl-) variables, they just return stuff that
		402	varies. Most of them make your expression sensitive to some events, for
		403	example using C<TW> (terminal width) means your expression is evaluated
		404	again when the terminal is resized.
439		405
440	=over 4	406	=over 4
441		407
442	=item clone $img	408	=item TX
443		409
444	Returns an exact copy of the image.	410	=item TY
445		411
446	=cut	412	Return the X and Y coordinates of the terminal window (the terminal
		413	window is the full window by default, and the character area only when in
		414	border-respect mode).
447		415
		416	Using these functions make your expression sensitive to window moves.
		417
		418	These functions are mainly useful to align images to the root window.
		419
		420	Example: load an image and align it so it looks as if anchored to the
		421	background.
		422
		423	move -TX, -TY, load "mybg.png"
		424
		425	=item TW
		426
		427	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		428	terminal window is the full window by default, and the character area only
		429	when in border-respect mode).
		430
		431	Using these functions make your expression sensitive to window resizes.
		432
		433	These functions are mainly useful to scale images, or to clip images to
		434	the window size to conserve memory.
		435
		436	Example: take the screen background, clip it to the window size, blur it a
		437	bit, align it to the window position and use it as background.
		438
		439	clip move -TX, -TY, once { blur 5, root }
		440
		441	=cut
		442
		443	sub TX() { $new->{again}{position} = 1; $x }
		444	sub TY() { $new->{again}{position} = 1; $y }
		445	sub TW() { $new->{again}{size} = 1; $w }
		446	sub TH() { $new->{again}{size} = 1; $h }
		447
		448	=item now
		449
		450	Returns the current time as (fractional) seconds since the epoch.
		451
		452	Using this expression does I<not> make your expression sensitive to time,
		453	but the next two functions do.
		454
		455	=item again $seconds
		456
		457	When this function is used the expression will be reevaluated again in
		458	C<$seconds> seconds.
		459
		460	Example: load some image and rotate it according to the time of day (as if it were
		461	the hour pointer of a clock). Update this image every minute.
		462
		463	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
		464
		465	=item counter $seconds
		466
		467	Like C<again>, but also returns an increasing counter value, starting at
		468	0, which might be useful for some simple animation effects.
		469
		470	=cut
		471
		472	sub now() { urxvt::NOW }
		473
		474	sub again($) {
		475	$new->{again}{time} = $_[0];
		476	}
		477
448	sub clone($) {	478	sub counter($) {
449	$_[0]->clone	479	$new->{again}{time} = $_[0];
		480	$self->{counter} + 0
450	}	481	}
		482
		483	=back
		484
		485	=head2 SHAPE CHANGING OPERATORS
		486
		487	The following operators modify the shape, size or position of the image.
		488
		489	=over 4
451		490
452	=item clip $img	491	=item clip $img
453		492
454	=item clip $width, $height, $img	493	=item clip $width, $height, $img
455		494
…		…
479	$img->sub_rect ($_[0], $_[1], $w, $h)	518	$img->sub_rect ($_[0], $_[1], $w, $h)
480	}	519	}
481		520
482	=item scale $img	521	=item scale $img
483		522
484	=item scale $size_percent, $img	523	=item scale $size_factor, $img
485		524
486	=item scale $width_percent, $height_percent, $img	525	=item scale $width_factor, $height_factor, $img
487		526
488	Scales the image by the given percentages in horizontal	527	Scales the image by the given factors in horizontal
489	(C<$width_percent>) and vertical (C<$height_percent>) direction.	528	(C<$width>) and vertical (C<$height>) direction.
490		529
491	If only one percentage is give, it is used for both directions.	530	If only one factor is give, it is used for both directions.
492		531
493	If no percentages are given, scales the image to the window size without	532	If no factors are given, scales the image to the window size without
494	keeping aspect.	533	keeping aspect.
495		534
496	=item resize $width, $height, $img	535	=item resize $width, $height, $img
497		536
498	Resizes the image to exactly C<$width> times C<$height> pixels.	537	Resizes the image to exactly C<$width> times C<$height> pixels.
499		538
500	=cut	539	=item fit $img
501		540
502	#TODO: maximise, maximise_fill?	541	=item fit $width, $height, $img
		542
		543	Fits the image into the given C<$width> and C<$height> without changing
		544	aspect, or the terminal size. That means it will be shrunk or grown until
		545	the whole image fits into the given area, possibly leaving borders.
		546
		547	=item cover $img
		548
		549	=item cover $width, $height, $img
		550
		551	Similar to C<fit>, but shrinks or grows until all of the area is covered
		552	by the image, so instead of potentially leaving borders, it will cut off
		553	image data that doesn't fit.
		554
		555	=cut
503		556
504	sub scale($;$;$) {	557	sub scale($;$;$) {
505	my $img = pop;	558	my $img = pop;
506		559
507	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	560	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
508	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	561	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
509	: $img->scale (TW, TH)	562	: $img->scale (TW, TH)
510	}	563	}
511		564
512	sub resize($$$) {	565	sub resize($$$) {
513	my $img = pop;	566	my $img = pop;
514	$img->scale ($_[0], $_[1])	567	$img->scale ($_[0], $_[1])
		568	}
		569
		570	sub fit($;$$) {
		571	my $img = pop;
		572	my $w = ($_[0] \|\| TW) / $img->w;
		573	my $h = ($_[1] \|\| TH) / $img->h;
		574	scale +(min $w, $h), $img
		575	}
		576
		577	sub cover($;$$) {
		578	my $img = pop;
		579	my $w = ($_[0] \|\| TW) / $img->w;
		580	my $h = ($_[1] \|\| TH) / $img->h;
		581	scale +(max $w, $h), $img
515	}	582	}
516		583
517	=item move $dx, $dy, $img	584	=item move $dx, $dy, $img
518		585
519	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	586	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
520	the vertical.	587	the vertical.
521		588
522	Example: move the image right by 20 pixels and down by 30.	589	Example: move the image right by 20 pixels and down by 30.
523		590
524	move 20, 30, ...	591	move 20, 30, ...
		592
		593	=item align $xalign, $yalign, $img
		594
		595	Aligns the image according to a factor - C<0> means the image is moved to
		596	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		597	exactly centered and C<1> means it touches the right or bottom edge.
		598
		599	Example: remove any visible border around an image, center it vertically but move
		600	it to the right hand side.
		601
		602	align 1, 0.5, pad $img
		603
		604	=item center $img
		605
		606	=item center $width, $height, $img
		607
		608	Centers the image, i.e. the center of the image is moved to the center of
		609	the terminal window (or the box specified by C<$width> and C<$height> if
		610	given).
		611
		612	Example: load an image and center it.
		613
		614	center pad load "mybg.png"
525		615
526	=item rootalign $img	616	=item rootalign $img
527		617
528	Moves the image so that it appears glued to the screen as opposed to the	618	Moves the image so that it appears glued to the screen as opposed to the
529	window. This gives the illusion of a larger area behind the window. It is	619	window. This gives the illusion of a larger area behind the window. It is
…		…
535	rootalign mirror load "mybg.png"	625	rootalign mirror load "mybg.png"
536		626
537	Example: take the screen background and align it, giving the illusion of	627	Example: take the screen background and align it, giving the illusion of
538	transparency as long as the window isn't in front of other windows.	628	transparency as long as the window isn't in front of other windows.
539		629
540	rootalign root	630	rootalign root
541		631
542	=cut	632	=cut
543		633
544	sub move($$;$) {	634	sub move($$;$) {
545	my $img = pop->clone;	635	my $img = pop->clone;
546	$img->move ($_[0], $_[1]);	636	$img->move ($_[0], $_[1]);
547	$img	637	$img
548	}	638	}
549		639
		640	sub align($;$$) {
		641	my $img = pop;
		642
		643	move $_[0] * (TW - $img->w),
		644	$_[1] * (TH - $img->h),
		645	$img
		646	}
		647
		648	sub center($;$$) {
		649	my $img = pop;
		650	my $w = $_[0] \|\| TW;
		651	my $h = $_[1] \|\| TH;
		652
		653	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		654	}
		655
550	sub rootalign($) {	656	sub rootalign($) {
551	move -TX, -TY, $_[0]	657	move -TX, -TY, $_[0]
552	}	658	}
553		659
		660	=item rotate $center_x, $center_y, $degrees
		661
		662	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		663	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		664	width/height).
		665
		666	#TODO# new width, height, maybe more operators?
		667
		668	Example: rotate the image by 90 degrees
		669
		670	=cut
		671
		672	sub rotate($$$$) {
		673	my $img = pop;
		674	$img->rotate (
		675	$_[0] * $img->w,
		676	$_[1] * $img->h,
		677	$_[2] * (3.14159265 / 180),
		678	)
		679	}
		680
		681	=back
		682
		683	=head2 COLOUR MODIFICATIONS
		684
		685	The following operators change the pixels of the image.
		686
		687	=over 4
		688
554	=item contrast $factor, $img	689	=item contrast $factor, $img
555		690
556	=item contrast $r, $g, $b, $img	691	=item contrast $r, $g, $b, $img
557		692
558	=item contrast $r, $g, $b, $a, $img	693	=item contrast $r, $g, $b, $a, $img
559		694
560	Adjusts the I<contrast> of an image.	695	Adjusts the I<contrast> of an image.
561		696
562	#TODO#	697	The first form applies a single C<$factor> to red, green and blue, the
		698	second form applies separate factors to each colour channel, and the last
		699	form includes the alpha channel.
563		700
		701	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		702	contrast.
		703
		704	Due to limitations in the underlying XRender extension, lowering contrast
		705	also reduces brightness, while increasing contrast currently also
		706	increases brightness.
		707
564	=item brightness $factor, $img	708	=item brightness $bias, $img
565		709
566	=item brightness $r, $g, $b, $img	710	=item brightness $r, $g, $b, $img
567		711
568	=item brightness $r, $g, $b, $a, $img	712	=item brightness $r, $g, $b, $a, $img
569		713
570	Adjusts the brightness of an image.	714	Adjusts the brightness of an image.
571		715
		716	The first form applies a single C<$bias> to red, green and blue, the
		717	second form applies separate biases to each colour channel, and the last
		718	form includes the alpha channel.
		719
		720	Values less than 0 reduce brightness, while values larger than 0 increase
		721	it. Useful range is from -1 to 1 - the former results in a black, the
		722	latter in a white picture.
		723
		724	Due to idiosyncrasies in the underlying XRender extension, biases less
		725	than zero can be I<very> slow.
		726
572	=cut	727	=cut
573		728
574	sub contrast($$;$$;$) {	729	sub contrast($$;$$;$) {
575	my $img = pop;	730	my $img = pop;
576	my ($r, $g, $b, $a) = @_;	731	my ($r, $g, $b, $a) = @_;
577		732
578	($g, $b) = ($r, $r) if @_ < 4;	733	($g, $b) = ($r, $r) if @_ < 3;
579	$a = 1 if @_ < 5;	734	$a = 1 if @_ < 4;
580		735
581	$img = $img->clone;	736	$img = $img->clone;
582	$img->contrast ($r, $g, $b, $a);	737	$img->contrast ($r, $g, $b, $a);
583	$img	738	$img
584	}	739	}
585		740
586	sub brightness($$;$$;$) {	741	sub brightness($$;$$;$) {
587	my $img = pop;	742	my $img = pop;
588	my ($r, $g, $b, $a) = @_;	743	my ($r, $g, $b, $a) = @_;
589		744
590	($g, $b) = ($r, $r) if @_ < 4;	745	($g, $b) = ($r, $r) if @_ < 3;
591	$a = 1 if @_ < 5;	746	$a = 1 if @_ < 4;
592		747
593	$img = $img->clone;	748	$img = $img->clone;
594	$img->brightness ($r, $g, $b, $a);	749	$img->brightness ($r, $g, $b, $a);
595	$img	750	$img
596	}	751	}
…		…
612	sub blur($$;$) {	767	sub blur($$;$) {
613	my $img = pop;	768	my $img = pop;
614	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	769	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
615	}	770	}
616		771
617	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees	772	=back
618		773
619	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	774	=head2 OTHER STUFF
620	pointer at C<$center_x> and C<$center_y> (specified as percentage of image
621	width/height), generating a new image with width C<$new_width> and height
622	C<$new_height>.
623		775
624	#TODO# new width, height, maybe more operators?	776	Anything that didn't fit any of the other categories, even after applying
		777	force and closing our eyes.
625		778
626	Example: rotate the image by 90 degrees	779	=over 4
627		780
628	=cut	781	=item once { ... }
629		782
630	sub rotate($$$$$$) {	783	This function takes a code block as argument, that is, one or more
631	my $img = pop;	784	statements enclosed by braces.
632	$img->rotate (	785
633	$_[0],	786	The trick is that this code block is only evaluated once - future calls
634	$_[1],	787	will simply return the original image (yes, it should only be used with
635	$_[2] * $img->w * .01,	788	images).
636	$_[3] * $img->h * .01,	789
637	$_[4] * (3.14159265 / 180),	790	This can be extremely useful to avoid redoign the same slow operations
		791	again and again- for example, if your background expression takes the root
		792	background, blurs it and then root-aligns it it would have to blur the
		793	root background on every window move or resize.
		794
		795	Putting the blur into a C<once> block will make sure the blur is only done
		796	once:
		797
		798	rootlign once { blur 10, root }
		799
		800	This leaves the question of how to force reevaluation of the block, in
		801	case the root background changes: Right now, all once blocks forget that
		802	they ahve been executed before each time the root background changes (if
		803	the expression is sensitive to that) or when C<once_again> is called.
		804
		805	=item once_again
		806
		807	Resets all C<once> block as if they had never been called, i.e. on the
		808	next call they will be reevaluated again.
		809
		810	=cut
		811
		812	sub once(&) {
		813	my $once = $self->{once_cache}{$_[0]+0} \|\|= do {
		814	local $new->{again};
		815	my @res = $_[0]();
		816	[$new->{again}, \@res]
638	)	817	};
		818
		819	$new->{again} = {
		820	%{ $new->{again} },
		821	%{ $once->[0] }
		822	};
		823
		824	# in scalar context we always return the first original result, which
		825	# is not quite how perl works.
		826	wantarray
		827	? @{ $once->[1] }
		828	: $once->[1][0]
		829	}
		830
		831	sub once_again() {
		832	delete $self->{once_cache};
639	}	833	}
640		834
641	=back	835	=back
642		836
643	=cut	837	=cut
…		…
686		880
687	# evaluate user expression	881	# evaluate user expression
688		882
689	my $img = eval { $self->{expr}->() };	883	my $img = eval { $self->{expr}->() };
690	warn $@ if $@;#d#	884	warn $@ if $@;#d#
691	die if !UNIVERSAL::isa $img, "urxvt::img";	885	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
692		886
693	$state->{size_sensitive} = 1	887	# if the expression is sensitive to external events, prepare reevaluation then
		888
		889	my $again = delete $state->{again};
		890
		891	$again->{size} = 1
694	if $img->repeat_mode != urxvt::RepeatNormal;	892	if $img->repeat_mode != urxvt::RepeatNormal;
695		893
696	# if the expression is sensitive to external events, prepare reevaluation then
697
698	my $repeat;
699
700	if (my $again = $state->{again}) {	894	if (my $again = $again->{time}) {
701	$repeat = 1;
702	my $self = $self;	895	my $self = $self;
703	$state->{timer} = $again == $old->{again}	896	$state->{timer} = $again == $old->{again}
704	? $old->{timer}	897	? $old->{timer}
705	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {	898	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
706	++$self->{counter};	899	++$self->{counter};
707	$self->recalculate	900	$self->recalculate
708	});	901	});
709	}	902	}
710		903
711	if (delete $state->{position_sensitive}) {	904	if ($again->{position}) {
712	$repeat = 1;
713	$self->enable (position_change => sub { $_[0]->recalculate });	905	$self->enable (position_change => sub { $_[0]->recalculate });
714	} else {	906	} else {
715	$self->disable ("position_change");	907	$self->disable ("position_change");
716	}	908	}
717		909
718	if (delete $state->{size_sensitive}) {	910	if ($again->{size}) {
719	$repeat = 1;
720	$self->enable (size_change => sub { $_[0]->recalculate });	911	$self->enable (size_change => sub { $_[0]->recalculate });
721	} else {	912	} else {
722	$self->disable ("size_change");	913	$self->disable ("size_change");
723	}	914	}
724		915
725	if (delete $state->{rootpmap_sensitive}) {	916	if ($again->{rootpmap}) {
726	$repeat = 1;
727	$self->enable (rootpmap_change => sub { $_[0]->recalculate });	917	$self->enable (rootpmap_change => sub {
		918	delete $_[0]{once_cache}; # this will override once-block values from
		919	$_[0]->recalculate;
		920	});
728	} else {	921	} else {
729	$self->disable ("rootpmap_change");	922	$self->disable ("rootpmap_change");
730	}	923	}
731		924
732	# clear stuff we no longer need	925	# clear stuff we no longer need
733		926
734	%$old = ();	927	%$old = ();
735		928
736	unless ($repeat) {	929	unless (%$again) {
737	delete $self->{state};	930	delete $self->{state};
738	delete $self->{expr};	931	delete $self->{expr};
739	}	932	}
740		933
741	# set background pixmap	934	# set background pixmap
…		…
746	}	939	}
747		940
748	sub on_start {	941	sub on_start {
749	my ($self) = @_;	942	my ($self) = @_;
750		943
751	my $expr = $self->x_resource ("background.expr")	944	my $expr = $self->x_resource ("%.expr")
752	or return;	945	or return;
753		946
		947	$self->has_render
		948	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		949
754	$self->set_expr (parse_expr $expr);	950	$self->set_expr (parse_expr $expr);
755	$self->{border} = $self->x_resource_boolean ("background.border");	951	$self->{border} = $self->x_resource_boolean ("%.border");
		952
		953	$MIN_INTERVAL = $self->x_resource ("%.interval");
756		954
757	()	955	()
758	}	956	}
759		957

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.42 by root, Sun Jun 10 10:42:19 2012 UTC vs. Revision 1.56 by root, Thu Jun 14 17:06:57 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.42 by root, Sun Jun 10 10:42:19 2012 UTC vs.
Revision 1.56 by root, Thu Jun 14 17:06:57 2012 UTC